Sound-absorbing structure



May 12, 1931. w. E. FOSTER SOUND ABSORBING STRUCTURE Filed April 17. 1929 g 5 i E z I INVENTOR WIL 1; IBM L. Fo-s TER'.

ATTORNEY Patented Ma 12, 1931 UNITED STATES WILLIAM? E. FOSTER, OF CLEVELAND HEIGHTS, OHIO SOUND-ABSOBBING STRUCTURE Application filed April 17, 1929. Serial No. 355,909.

This invention relates to a structure for producing an improvement in the acoustics of auditoriums.

Heretofore, it has been regular practice to apply sound-absorbing material to the walls and ceiling of an auditorium for the purpose of preventing echo. It is also a well-known fact that the seat cushions of a church auditorium, for instance, maybe depended upon 1 as a sound-absorbing means, although the sound-absorbing effect of the cushions is automatically eliminated when the auditorium becomes filled. Moreover, cushions are omitted in most cases today,'due to excessive cost, and

can not well be later added, as explained isempty is below.

In an actual instance of a particular church auditorium known to the present applicant, the period of vibration when the auditorium of sound will continue for 3.5 seconds. Then when the same auditorium is completely filled, the period of vibration is reduced to 1.8.

In this particular instance, the ideal condition with respect to the period of vibration is 2. Thus, it is quite apparent that when the auditorium is empty, there would be a pronounced vibration of sound resulting in the objectionable echo, and the ideal condition is realized only when the auditorium is almost completely filled. In other words, the period of vibration varies according to the number of people in the auditorium and thus there results a variable factor beyond control, so far as the ideal condition with respect to vibration is concerned.

With the present existing condition as above briefly referred to, there has been experienced a need in some instances for a [1 I I greater degree of sound-absorbing capaclty,

That is to say, the vibration The problem, as above indicated, has been practically solved, as a result of the discovery that the application of a sound-absorbing means to the under-side of the pew or other form of seat in the church or other auditorium may be depended upon to accomplish the purpose as above outlined. In this'way, there is aiforded the increased surface area for the application or" sound-absorbing material; and such material when applied in this manner, will be in the path of the sound which is reflected from the floor of the auditorium. Furthermore, the sound-absorbing effect of such material, when applied in this manner, will be realized at all times to the proper degree, that is, regardless of whether the audi-, torium is filled or empty. In this way, the period of vibration of the auditorium when empty may be made to approximate the ideal condition without interfering with the same ideal condition when the auditorium is completely filled. The legs of the occupants of the seats, to the under-side of which the sound-absorbing material is applied, will somewhat reduce the sound-absorbing effect of such material when the auditorium is filled, yet this reduction is compensated for by the sound-absorbing eiiect oi the occupants, and there is thus obtained the proper degree of sound absorption at all times regardless of the number of people in the auditorium;

Also, the sound that is produced by the shutfiing of the feet of those occupying the seats will be absorbed in a very effective manner by means of the present invention. The effect of the sound-absorbing material applied to the under-side of the seats is thus automatically regulated according to the degree to which the auditorium is filled. In fact, practical experience has already demonstrated that the sound-absorbing material when applied to the under-side of the seats, as herein disclosed, may be depended upon as an automatically compensating variable for all conditions of the auditorium, that is, regardless of the degree to which the auditorium may be filled. There may be employed any desired sound-absorbing material and it may be applied to the extent required by the particular set of conditions in a given case. v f

Fig. 1 is a perspective view of a church pew embodying my present invention; Fig. 2 is a 5 sectional view taken on line 2'2 of Fig. 1;

and Fig. 3 is an inverted plan view of Fig. 1i

. Referring to the accompanying drawings, the sound-absorbing material 11s indicated as applied to the under-side of the seat portion 2 thereof will be exposed to the 'soun'd vibrations. In the present case, the pew 1s 'p ro- 'vided with the legs 3, while the remaining 15 portion of the pew is left open at the underside thereof. 7 The sound-absorbing material manufacturer to the under-side of the pew as aninsert and may in such case be considered as forming a part of the: pew in its original construction. Various other modifications may be adopted without departing from the spirit of the present invention.

Another advantage consists in the factthat thesound-absorbing material may be applied to the under-side of a pew which has already been installed in a church auditorium. But

cushions can not he added to pews which were not originallydesigned therefor, for the reason that the curvature of the pews must be designed originally according to whether or not cushions are to be used. addition of cushions to pews not originally so designed would destroy the proper effective curvature of the pews. Furthermore, the application of the present invention to a church pew or the like, either during the process of construction thereof or after its installation,

7 is comparatively inexpensive and may be applied in a convenient manner without involving the use of scaffolding or the like which is required in the application ofsoundabsorbing material to the walls and ceiling of an auditorium. Also, the sound-abs0rbing material, when applied in the manner herein described, is practically out of View and hence is free of any objection because of the appearance of the particular material selected; and at the same time, the sound absorbing material is arranged in such position as to be protected against damage. .The sound-absorbing material maybe applied to Q0 only as many pews as may be necessary in a particular. case, and yet such an arran'gement is not unsightlysince it is'not noticeable to the public. y 7

As above stated, the principal advantage resulting from the present invention resides of the pew, the lower part of 'WlllCll'lS so cnnstructed and arranged that the under-side.

Then the later ing a seat having its under-side exposed to sound vibrations, and being provided upon its under-side with sound-absorbing material capableof greater sound absorption than the material of the seat itself.

3. The combination of an inflexible seat portion having its underside exposed to sound vibrations, and separatesound-absorbside thereof, said materialhaving a greater sound-absorbing capacity than the material of the seat portion itself.

4. A device of the class described, compris ing an inflexible seat portion having its under-side; exposed to sound vibrations, and

being provided upon its" under-side with sound-absorbing means capable of a relatively high degree of sound absorption.

5. A device of the class described comprisng a seat portion formed ofv inflexible material and being provided therebeneath with posed directly to the sound waves. reflected from the floor and having a greater soundabsorbing capacity than the material of the seat portion itself.

- In testimonywhereof, I hereby affix my ing material secured directly to the undersoundabsorbing means, said means being ex- 

